This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The prevalence of B12 deficiency in sickle cell disease (SCD) is not known though our preliminary data suggest that it may be higher in the non-SCD population. Patients with SCD could be more prone to B12 deficiency due to the multiple factors. We recently published a retrospective study, which found low B12 levels in adult SCD patients when compared with those in anemic African Americans (AA) without SCD. Based on our preliminary data we plan to determine if there is a differenced of at least 373pg/ml in mean B12 levels between AAs with and without SCD. We also found that B12 deficiency is more common in AA with SCD and that SCD-B12 deficient patients tend to be younger and more likely to be males compared to B12 deficient subjects without SCD. We plan to screen blood samples for levels of B12, foliate, methylamlonic acid (MMA), homocysteine, intrinsic factor antibody, gastrin and helicobacter pylori antibody in two groups of subjects: a group of 75 SCD patients, and a control group of 75 non-SCD patients who present to their primary care office. A comprehensive history and physical examination will be obtained in each of these patients. For those patients with low B12 levels, further workup will include helicobacter pylori stool antigen. Finally, the clinical and laboratory parameters will be compared between the two groups and differences tested for statistical significance. All patients who have B12 deficiency will be referred to their primary care physicians for treatment.